In my copending patent applications Ser. No. 516,688 filed Oct. 21, 1974 now U.S. Pat. No. 3,911,666, entitled ACTUATING MECHANISMS FOR WRIST INSTRUMENTS; Ser. No. 556,335 filed Mar. 7, 1975 now U.S. Pat. No. 3,946,173, entitled WRIST ACTUATED PRESSURE SWITCH FOR WATCHES; and Ser. No. 538,743 filed Jan. 6, 1975 now U.S. Pat. No. 3,916,664, entitled ACCELERATION/DECELERATION ACTUATING MECHANISM FOR WRIST INSTRUMENTS, there are disclosed electronic watches of the digital read-out type, the display constituting either light emitting-diodes or liquid crystals. These applications deal with inertia and/or pressure actuated switches for rendering the display visible. Such switches as our described and shown may be used in place of or in conjunction with the conventional push-button switch on the side of the watch casing which is required to be depressed in order to render the display visible.
Even though inertia or pressure responsive switches are useful in that they eliminate the necessity for the user to use his other hand to actuate the display, most watches still include the normal manually operable push button and in certain applications or uses, it may be desirable to provide this specific type of manual control; for example, in environments where the wrist watch might be subject to constant shaking or battering about thus raising the possibility of inadvertent operation of inertia type switches. The manually operable push button type switch normally used, however, is a relatively expensive item. Generally, up to five separate parts are required. First, there is a sleeve in which a plunger or pin can move, this sleeve being fixed within an opening in the side of the watch casing. Also normally provided is a coiled spring surrounding the pin and biasing it away from an internal contact within the watch casing. A sealing O-ring is also provided as well as an end contact rivet for the pin. Essentially, the only function of the switch is to electrically connect an internal contact to the watch casing which serves as a ground or return circuit. The reliability as well as the expense of digital type watches could be reduced by merely simplifying the actuating push button type of switch. However, the art is devoid at the present time of any type of control other than that described.